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Resolved 2G - New alternator doesn't charge.

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zFrostbite

Probationary Member
13
1
May 15, 2016
Vestlandet, Europe
Hey.

A while back my alternator started only charging a bit and eventually stopped charging after I reached higher RPM. In the meantime I also had something that looked like a short, because when I turned off the power to my gauges, they would still receive enough voltage to actually turn on and function. I settled with the thought of the alternator being broken so I bought a new one. The new one doesn't charge at all and I'm unsure if there is a short now. I'd like to get some tips, please. Also I wonder what specific voltages I would get from that 4-pin alternator plug? I get 12V on the red wire and I got something like 4V on another one and the two others were dead. Does anyone know what voltages to expect here? To be honest it also looked like it had a slight burn mark from the 12V pin to the pin next to it, but I'm not certain.
The battery is fully charged and I have tried with two different batteries. It had about 12.5V when I start the car and it falls to about 11.4V when running. I've tried increasing the throttle a bit also, but nothing happens. I'm doing the readings with a multimeter at the battery terminals. I've also checked for continuity between the battery and alternator and checked that it's grounded properly.
Thanks in advance..
-Frostbite
 
Solution
If you're reading this in the future and experience this problem, never trust a cheap alternator.. Thanks for helping everyone. The new, expensive, alternator has worked like a charm.
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When running you should get around 13.8v without other accessories on. Sound like your new alternator is bad. Don't know about Europe but here in the USA we usually recommend only buying Mitsubishi OE alternators. A lot of the time the "parts stores" cheapo stuff is bad right out of the box & if you get a working one it typically will fail quickly. What brand alternator did you purchase? Also, not sure what year maybe around 2005, but a proper year Galant alternator is a direct bolt-on & puts out 90A instead of the 2G 75A & people will switch as an upgrade.
 
Upvote0
d1prospect said:
Question although you may have done it already. Does the belt have proper tension. Also worse case you gotta start alt plug harness and trace from there
Click to expand...
It's actually a biiit loose and is making s bit of sound. However, I checked that the pulley is rotating. I kind of left that alone, but I'll definately tighten it just to be sure. How can I know what the readings should be on that 4pin plug?
Thank you!
Mello said:
When running you should get around 13.8v without other accessories on. Sound like your new alternator is bad. Don't know about Europe but here in the USA we usually recommend only buying Mitsubishi OE alternators. A lot of the time the "parts stores" cheapo stuff is bad right out of the box & if you get a working one it typically will fail quickly. What brand alternator did you purchase? Also, not sure what year maybe around 2005, but a proper year Galant alternator is a direct bolt-on & puts out 90A instead of the 2G 75A & people will switch as an upgrade.
Click to expand...
I don't know, to be honest. I ordered it from Ace Alternators on eBay. Should I get it checked? I couldn't find an alternator here in Norway, didn't try asking the dealer but they would've drained my bank account, I'm afraid..
Thank you
 
Upvote0
I just came back from a store that tests alternators and they said it was fried. They also said it looked sketchy because it lacked any form of identification number. Furthermore, they obviously couldn't say if my car fried it or if it was broken... How would I troubleshoot this?
 
Upvote0
- European DSM's are different than USA ones so keep that in mind. So I'm speaking for USA ones but much should still apply to yours.

- Make sure the power steering pump hasn't dripped oil onto the alternator - that kills them for sure.

- Check the high amp (100-120 amp) alternator fuse in engine bay.

- Make sure the dash charge light works (should be on when key is on but engine not started). It must work to supply voltage to the alt field coil or the alt won't charge.

- Belt must be tight or it won't charge especially at higher rpm or higher electrical loads.

- The 4 wire alt plug: Red goes to battery positive. Black-yellow (sometimes blue) goes to the dash charge light (should not be zero if alt is charging - if zero the dash charge light should be on). Green is a electrical load sensing wire for the ECU and can be anything based on electrical load. White is a ECU control wire and normally floats so can be anything (ECU temporarily grounds it to force alt into a "no output mode" when extra engine power is required, like full throttle, however some after market alts don't support this).

- Here in the USA the Galant alt can be a direct replacement: http://www.dsmtuners.com/threads/alternator-battery-question.415719/#post-152823625
 
Last edited:
Upvote1
+1 for checking the alt fuse. Always buy OEM alternators. No exceptions! Every vehicle. Doesn't matter if it's Napa, AutoZone, advanced, O'Reilley, or any chain distributor, they are all junk and even though some are made in the u.s they still use knockoff regulators and such. Always buy oem parts from extremepsi or a legit distributor when having issues or you will never know if you got a junk part in the first place. Been there, done that. You can get oil, filters, bulbs, and spark plugs at a chain distributor, that's about it.
 
Upvote0
Love my '96 Galant alternator on my '90. Direct bolt on and plug and play. If you can find one in Europe, it is a very easy upgrade!
 
Upvote0
luv2rallye said:
- European DSM's are different than USA ones so keep that in mind. So I'm speaking for USA ones but much should still apply to yours.

- Make sure the power steering pump hasn't dripped oil onto the alternator - that kills them for sure.

- Check the high amp (100-120 amp) alternator fuse in engine bay.

- Make sure the dash charge light works (should be on when key is on but engine not started). It must work to supply voltage to the alt field coil or the alt won't charge.

- Belt must be tight or it won't charge especially at higher rpm or higher electrical loads.

- The 4 wire alt plug: Red goes to battery positive. Black-yellow (sometimes blue) goes to the dash charge light (should not be zero if alt is charging - if zero the dash charge light should be on). Green is a electrical load sensing wire for the ECU and can be anything based on electrical load. White is a ECU control wire and normally floats so can be anything (ECU temporarily grounds it to force alt into a "no output mode" when extra engine power is required, like full throttle, however some after market alts don't support this).

- Here in the USA the Galant alt can be a direct replacement: http://www.dsmtuners.com/threads/alternator-battery-question.415719/#post-152823625
Click to expand...
Thanks ALOT for explaining the 4pin connector and the other steps. I have spilled power steering fluid on the first alternator, so I was very carefull this time and didn't spill any. I have checked the fuse and its OK. The dash light works, I tried unplugging the 4pin connector and the dash light disappeared, but reappeared when I plugged the connector back in. Belt did whine quite a bit, so that should've been tighter, but that can't have fried it?? The store said it was fried so I guess I'm getting an OEM one.. Do you think there is any possibility that the car's electrical wiring may have fried this alternator, or do you think I bought a faulty one? The shorts I explained I've been having before COULD have been the alternator itself giving in?? Thank you very much.

bizie said:
+1 for checking the alt fuse. Always buy OEM alternators. No exceptions! Every vehicle. Doesn't matter if it's Napa, AutoZone, advanced, O'Reilley, or any chain distributor, they are all junk and even though some are made in the u.s they still use knockoff regulators and such. Always buy oem parts from extremepsi or a legit distributor when having issues or you will never know if you got a junk part in the first place. Been there, done that. You can get oil, filters, bulbs, and spark plugs at a chain distributor, that's about it.
Click to expand...
Alright, lesson learned. I'll get an OEM one, but what should I do as precaution before actually installing the OEM alternator? I don't feel like frying that one aswell.
 
Upvote0
It probably wasn't you. Probably the junky alternator. I've bought two new ones in a row from Napa before and neither worked. Got oem and .it was like magic. The alternator has one job, put out volts. The only ways to fry a new alternator is by not using the alt fuse and having a short or by having too much heat in the bay causing it to overheat. Oem ones are more resistant to the over heating. Also make sure your alt fuse isnt slightly broken making periodic partial contact.
 
Upvote0
I bought a 150 amp alternator off of Amazon. Puts out 14.6 to a low of 13.9 with headlights on and my high powered stereo system. Amazon is your friend and I will mention that I upgraded the feed to my alternator with a lower guage wire from the battery to the fuse box to the altenator. Works like a charm had it since last year December no problems. i dont think its OE even though OE will not hurt. I also have cool air blowing on my alternator which helps it out 1000% voltage wise and longevity wise. Thanks to ducting my radiator. Heat rapidly deteriorates the alternator whether stock or aftermarket.
 
Upvote0
bizie said:
It probably wasn't you. Probably the junky alternator. I've bought two new ones in a row from Napa before and neither worked. Got oem and .it was like magic. The alternator has one job, put out volts. The only ways to fry a new alternator is by not using the alt fuse and having a short or by having too much heat in the bay causing it to overheat. Oem ones are more resistant to the over heating. Also make sure your alt fuse isnt slightly broken making periodic partial contact.
Click to expand...
Alright, that does fill me up with a little bit more hope. I'll talk to the dealer tomorrow and have one ordered. I'll also double check the fuse. As for the short I experienced earlier, is there a chance that it was caused by the failing alternator? When it occured it would drop to like 10V and I'd see all kinds of things in my gauges, my temp gauge would jump up to max(aftermarket gauge) and lights would dim. Even if I cut the power to the gauges, they'd come on, either at full strength(lights wise) or at somewhat of a lower voltage. If I then turned on the rear defogger, it would really struggle and almost die out. Does this sound like a short or the alternator? I cant remember if I spilled steering fluid onto the alternator before or after that happened, but I did spill it at some point...
 
Upvote0
Upvote0
I can't really find anything that would suggest a problem, so I guess I'm just going to have to try when I get the alternator tomorrow. A little bit too exciting.. Thanks for the "finding a short" guide! However, I can't really seem to find any shorts, so if there are shorts, I'm guessing they're not that significant. I'm afraid I'm just going to have to take my chances on this one
 
Upvote0
If you're reading this in the future and experience this problem, never trust a cheap alternator.. Thanks for helping everyone. The new, expensive, alternator has worked like a charm.
 
Upvote0
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